Automatic Table Tennis Server

ABSTRACT

This invention relates to a unique design of an automatic table tennis server that can automatically eject table tennis balls in such a way that each successively ejected ball carries different spin, such as top-spin, any combination of top-spin and side-spin, side-spin, any combination of under-spin and side-spin, as well as under-spin. The automatic table tennis server provided in this invention can effectively improve the skills of a table tennis player in mastering various types of spins. The automatic table tennis server presented in this invention is simple in mechanical design, simple in electronic control and inexpensive in product manufacturing.

BACKGROUND OF THE INVENTION

Table tennis, or ping-pong, is a popular sport in both competition and recreation. An automatic table tennis server device is a device that can eject table tennis balls from one side of the table tennis table to the other side of the table, thus, a player can play with the table tennis server device. This invention relates to a unique and simple mechanical design of an automatic table tennis server that can automatically eject table tennis balls in such a way that each successively ejected ball carries different spin, such as top-spin, any combination of top-spin and side-spin, side-spin, any combination of under-spin and side-spin, as well as under-spin.

In view of prior arts of automatic or robot table tennis server devices, there are basically two types of mechanism designs with regard to the way a ball is ejected. The first type utilizes the pneumatic/pressure-air to eject table tennis balls. Examples are U.S. Pat. No. 2,508,461 in 1950 to Lemon, U.S. Pat. No. 3,917,265 in 1975 to Schrier and Eichner, U.S. Pat. No. 3,911,888 in 1977 to Horvath, U.S. Pat. No. 4,002,336 in 1977 to Beaver et al., U.S. Pat. No. 4,270,511 in 1981 to Ehama, U.S. Pat. No. 4,559,918 in 1985 Ballerin et al., U.S. Pat. No. 4,735,405 in 1988 to Marocco, U.S. Pat. No. 4,886,269 in 1989 to Marocco. However, none of them can change the ball spin automatically during the table tennis play.

The second type employs motorized wheels to eject table tennis balls. Examples include U.S. Pat. No. 2,087,575 in 1937 to Littell and Wenecek., U.S. Pat. No. 2,793,636 in 1937 to Cook, U.S. Pat. No. 3,794,011 in 1974 to Newgarden, U.S. Pat. No. 3,878,827 in 1975 to Newgarden, U.S. Pat. No. 4,116,438 in 1978 to Berliner, European Patent Application Publication No. 503176 A1 in 1992 to Lien, U.S. Pat. No. 5,181,501 in 1993 to Lien, U.S. Pat. No. 6,220,236 in 2001 to Dillard, U.S. Pat. No. 6,604,517 in 2003 to Chao et al. However, none of them can change the ball spin automatically during the table tennis play. And most noticeably, Newgarden or Newgarden and his partners have disclosed a number of inventions that include UK Patent Application Publication No. GB 2,173,11A, U.S. Pat. No. 4,844,458 in 1989, U.S. Pat. No. 4,854,588 in 1989, U.S. Pat. No. 4,917,380 in 1990, U.S. Pat. No. 5,335,905 in 1994, U.S. Pat. No. 5,383,658 in 1995, U.S. Pat. No. 5,485,995 in 1996, European Patent No. 0663842 B1 in 1998. Their design, however, are all based on a similar mechanism using a single motorized wheel to eject table tennis balls and some include a catching net for recycling the returning table tennis balls. In all their versions, one has to manually rotate the ejecting head to be able to change the spin of table tennis balls.

Another example of using motorized wheels to eject table tennis balls is disclosed in U.S. Pat. No. 5,607,151 in 1997 to Daley. The unique feature of their design is to use a single motorized wheel to eject a ball at a certain speed and then two separate motorized wheels to control the spin, the speed of which is independent to that ejected by the single wheel. Prior arts had a limitation being unable to reverse the spin on balls successively in less than one second. The invention in this U.S. Pat. No. 5,607,151 makes it possible owing to the above-mentioned unique design feature. Their design, however, is limited to only three types of spins, i.e., top-spin, under-spin and no-spin. Even though their design can provide automatically randomized speed control of the ball spins through the two motorized wheels, it is still limited to the above-mentioned three basic types of spins, i.e. top-spin, under-spin and no-spin. This is because the two motorized wheels in their design are fixed in a specific plan, in fact the vertical plan, thus unable to produce the side-spins or any combined spin between top-spin and side-spin or between under-spin and side-spin during the table tennis play. In the reality of table tennis play, players may create any type of ball spin.

In recently granted inventions, U.S. Pat. No. 6,220,452 in 2001 to Yamashita et al., U.S. Pat. No. 6,200,236 in 2001 to Minami et al. and U.S. Pat. No. 6,383,097 in 2002 to Minami et al., all from the same group of inventors, a mechanism involving dual motorized wheels is used to eject table tennis balls. However, the creation of spins as described in above-mentioned inventions relies on sophisticated computer programs and computer control, thus the system is complex and expensive to manufacture. Another example of using computer programs and computer control to produce the spins of table tennis balls is disclosed in U.S. Pat. No. 6,186,132 in 2001 to Ko.

In view of all prior arts related to table tennis serving devices, other than those using computer programs and computer control as above-described, none of them can achieve the objective that each successively ejected ball carries different spin, such as top-spin, any combination of top-spin and side-spin, side-spin, any combination of under-spin and side-spin, as well as under-spin. Although the automatic table tennis servers that use computer programs and computer control may achieve the objective of creating different spin for each successively ejected ball, it is sophisticated in design and expensive to manufacture.

OBJECTIVES OF THE INVENTION

Therefore it is the objective of this invention to develop a mechanical-based automatic table tennis server that can automatically eject the table tennis balls in such a way that each successively ejected ball carries different spin, such as top-spin, any combination of top-spin and side-spin, side-spin, any combination of under-spin and side-spin, as well as under-spin, which makes the table tennis play more realistic and more challenge. It is also the objective of this invention to develop a simple and cost effective automatic table tennis server that can eject the table tennis balls in such a way that each successively ejected ball carries different spin without the need to use complex computer programs and computer control.

The automatic table tennis server provided in this invention can effectively improve the skills of a table tennis player in mastering various types of ball spins.

The novel feature in this invention is a unique and simple structure design of an automatic table tennis server that can eject table tennis balls in such a way that each successively ejected ball carries different spin, such as top-spin, any combination of top-spin and side-spin, side-spin, any combination of under-spin and side-spin, as well as under-spin, which means at one time, for instance, the spin is a top-spin, while at another time, it may be a combination of top-spin (say 72%) and side-spin (say 28%). At each time a table tennis ball is ejected, it carries a different spin, for instance, a top-spin, a combination of top-spin and side-spin, a side-spin, a combination of under-spin and side-spin, or an under-spin.

Further, the player can have an option to only practice one specific spin by simply using an on-or-off switch to obtain the desired spin.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view of the automatic table tennis server provided in this invention.

FIG. 2 is a perspective view of one example of the embodiments of the rotatable chamber provided in this invention.

FIG. 3 is a side view of the automatic table tennis server provided in this invention.

FIG. 4 is a front view of the automatic table tennis server provided in this invention.

SUMMARY OF THE INVENTION

The novel idea of this invention is to provide an automatic table tennis server that is simple in structure design but has the advanced functionality that otherwise may only be possible using sophisticated and expensive computer programs and computer control. FIG. 1 demonstrates an example of an automatic table tennis server that can be provided by this invention. FIG. 2 shows an example embodiment of a uniquely designed rotatable chamber that is included in the automatic table tennis server presented in this invention. The rotatable chamber is designed to have a unique shape that, first, functions as ball ejection unit with secure mounting of an assembly of motor, wheel and rubber pad at its front-end portion; second, functions as a cylindrical shaft driven by a motorized gear/belt driving unit; and third, also functions as passageway for table tennis balls to pass through and reach the ball-ejection end. Shown in FIG. 2 is an example of the embodiments of the rotatable chamber in the form of a single component with the front-end portion being shaped like a slotted rectangular tube and the rest portion being shaped like round tube with a built-in groove functioning as a pulley to be used in a motorized belt driving system. The rotatable chamber based on the embodiments provided in this invention may be in the form of a single component, or of two halves jointed together, or of multiple parts assembled together.

The rotatable chamber, either a component or an assembled or jointed entity, can be driven by a gear or belt system through an electric motor including but not limited to a direct current (DC) motor, an alternate current (AC) motor or a stepping motor. Since the ball ejection unit including motorized wheel and rubber pad is fixed on the rotatable chamber, each successively ejected ball carries different spin as the rotatable chamber rotates. Then a mechanical limit or toggle switch, or a proximity sensor, can be used for automatically reversing the rotational direction of the motorized gear or belt unit that drives the rotatable chamber. Therefore, the automatic table tennis server provided in this invention can automatically eject the table tennis ball in such a way that each successively ejected ball carries different spin, such as top-spin, any combination of top-spin and side-spin, side-spin, any combination of under-spin and side-spin, as well as under-spin.

Furthermore the rotatable chamber, either a single component or an assembled or jointed entity, can be applied as a unit to form a complete automatic table tennis sever system, thus enabling to eject the table tennis balls in such a way that each successively ejected ball carries different spin, such as top-spin, any combination of top-spin and side-spin, side-spin, any combination of under-spin and side-spin, as well as under-spin. A complete automatic table tennis sever system typically includes other functional units usually found in a complete automatic table tennis server system, for example including but not limited to, a hopper for containing table tennis balls, a mechanism for feeding table tennis balls, a mechanism for controlling the swing movement of a table tennis server, a mechanism for controlling the tilt or elevation angle of a table tennis server, an electronic control unit, a stand as a support base, and an optional catching net for recycling returned table tennis balls.

DETAILED DESCRIPTION OF THE INVENTION

An automatic table tennis server 1, as an example of the embodiments provided in this invention, is shown in FIG. 3 for the side view and FIG. 4 for the front view. The table tennis balls are contained inside the hopper 2. A wheel 3 is used to eject a table tennis ball that is fed in between the wheel 3 and the rubber pad 14 (see both FIGS. 3 and 4). The motor 4 (see both FIGS. 3 and 4) is used to drive the wheel 3 and a mounting support 5 is attached on the front end (i.e. ball-ejection end) of the rotatable chamber 13 through a number of bolts 11 and nuts 12. A metal strip 6 is used to secure the motor 4 into the mounting support 5. The rubber pad 14 is bonded onto a support plate 17 that is secured onto the front end of the rotatable chamber 13 through a number of bolts 15 and nuts 16.

As mentioned earlier, the front end (i.e. ball ejection end) of the rotatable chamber 13 is shaped like a slotted rectangular tube to allow the secure mounting of the assembly of wheel 3, motor 4 and mounting support 5, as well as rubber pad 14 and the corresponding support plate 17, while the rest portion of the rotatable chamber 13 is shaped as cylindrical surface that rotates about the center axis 40 on the two journal bearings 18 and 26 as shown in FIG. 3. The rotatable chamber 13 can then be driven by a motorized gearbox or belt-pulley system. Shown in FIGS. 3 and 4 is a motorized belt-pulley system where the motor 7 drives the belt 9 through a small pulley 8, then the belt 9 drives the big pulley 45 which is assembled onto the cylindrical portion of the rotatable chamber 13. The big pulley 45 may simply be a built-in groove (as a portion of the rotatable chamber 13) that functions as a pulley like the one shown in FIG. 2. A collar 19, being secured to the cylindrical surface of the rotatable chamber 13 by a set screw 10, is used to set the axial clearance for the rotatable chamber 13.

A limit or toggle switch 20 is mounted on the support frame 24 and a mechanical stop 21 is fixed on the rotatable chamber 13. The limit or toggle switch 20 is used to reverse the rotating direction of motor 7 that drives the rotatable chamber 13. Because the assembly of wheel 3, motor 4 and rubber pad 14 are fixed on the rotatable chamber 13, when the rotatable chamber 13 rotates, each successively ejected table tennis ball will carry different spin. The types of spins include top-spin, any combination of top-spin and side-spin, side-spin, any combination of under-spin and side-spin, as well as under-spin. A proximity sensor including the sensor 22 and the actuator 23 may be introduced to play the same role as the limit or toggle switch 20 and the mechanical stop 21. This is because when the actuator 23 gets close to the sensor 22, it can trigger an action to reverse the rotating direction of the motor 7 and thus that of the rotatable chamber 13. The limit or toggle switch 20 and the proximity sensor 22 may be jointly used to give more control options.

As an example of the table tennis ball feeding mechanism, a mechanical linkage system is presented in this invention, which includes a push rod 27 that forces a ball into the rotatable chamber 13, a journal bearing 28, a bearing support block 29, a connecting linkage 30 with two pins 31 and 35, a driving linkage 32, a motor 33, a motor mounting support 34. The mechanical linkage system as described is mounted on a bracket 36. A plate 37 is used to hold a table tennis ball at the position ready for being pushed into the rotatable chamber 13. A small spring 42 (see both FIGS. 3 and 4) is used to prevent a table tennis ball that is already inside the rotatable chamber 13 from moving backwards. The column 25 is attached to the base stand 41 through a bolt 38, two nuts 43 and a thumb nut 39 (see both FIGS. 3 and 4). Because the hopper 2, the support frame 24 and the bracket 36 are attached to the column 25 (see FIG. 3), the automatic table tennis server can be manually adjusted by rotating about the bolt 38 to get a desired tilt or elevation angle. The thumb nut 39 is used to loose or fasten the column 25. An electronic control box 44 is also mounted on the base stand 41. The base stand 41 may be in other form of structure, for instance, a mobile stand that can move around on the ground.

The functionality of the automatic table tennis server presented in this invention may be increased by adding a motor based unit to control the swing movement of the table tennis server, thus the table tennis balls can be projected at varying swing locations on the table over the player's side. The functionality of the automatic table tennis server presented in this invention may be further increased by adding a motor based unit to control the tilt or elevation angle of the table tennis server, thus the table tennis server can automatically project the balls at varying distances on the table over the player's side.

In addition, the player can have an option to only practice one specific spin by simply adjusting the rotational position of the rotatable chamber 13 through an on-or-off switch that controls the motor 7.

The automatic table tennis server provided in this invention can effectively improve the skills of a table tennis player in mastering various types of spins.

The automatic table tennis server presented in this invention is a simple but novel design that is unique in mechanical structure, simple in electronic control and inexpensive in product manufacturing. 

1. An automatic table tennis server capable of automatically ejecting the table tennis balls in such a way that each successively ejected table tennis ball carries different spin, such as top-spin, any combination of top-spin and side-spin, side-spin, any combination of under-spin and side-spin, as well as under-spin without the need to use computer programs and computer control.
 2. The automatic table tennis server of claim 1 including a rotatable chamber being equipped with at least one limit or toggle switch and/or at least one proximity sensor, functioning as automatic reverse of the rotational direction of a motorized gear/belt driving system that drives the said rotatable chamber.
 3. The automatic table tennis server of claim 2 wherein the said rotatable chamber, either in the form of a single component or an entity from assembly or joining of multiple parts, with its front-end portion being shaped like a slotted rectangular tube, or any slotted elliptical/polygonal tube, to allow a secure mount of a motorized wheel and a rubber pad, functioning as ball ejection; and with its rest portion being shaped like a hollowed round tube, functioning both as a shaft driven by said motorized gear/belt driving system and as a ball passageway to reach the said front-end portion where the ball shall be ejected. 